Design consideration of two candidate propellers for ice breaking vessel

Abstract

The propellers for ships operating in the Antarctic and Arctic regions encounter fragments of ice and sometimes are damaged according to the severity of ice load. The design of propellers for such ships is quite different from that of conventional ships, since in designing the propeller geometry, not only hydrodynamic performances requested are to be satisfied but also blades are to be strong enough to stand ice-milling load. This study deals with the effect of the geometry of the propeller on performances in open-water and in ice. Two candidate propellers with different blade shape, ogival and lenticular sections were designed for the Japanese icebreaker SHIRASE, by employing the existing ice-milling load estimation method of JAGODKIN and the blade-propeller shaft strength calculation method of IGNATJEV. The results show the specific features of each propeller blade section for propellers of icebreakers. Also, the existing methods for estimating the ice-load are found useful.